source: mainline/kernel/arch/ia32/src/boot/boot.S@ e16e0d59

#
# Copyright (c) 2001-2004 Jakub Jermar
# Copyright (c) 2005-2006 Martin Decky
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

#include <arch/boot/boot.h>
#include <arch/boot/memmap.h>
#include <arch/mm/page.h>
#include <arch/pm.h>

#define START_STACK (BOOT_OFFSET - BOOT_STACK_SIZE)

.section K_TEXT_START, "ax"

.code32
.align 4
.global multiboot_image_start
multiboot_header:
        .long MULTIBOOT_HEADER_MAGIC
        .long MULTIBOOT_HEADER_FLAGS
        .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)  # checksum
        .long multiboot_header
        .long unmapped_ktext_start
        .long 0
        .long 0
        .long multiboot_image_start

multiboot_image_start:
        cld
        movl $START_STACK, %esp     # initialize stack pointer
        lgdt KA2PA(bootstrap_gdtr)  # initialize Global Descriptor Table register
        
        movw $gdtselector(KDATA_DES), %cx
        movw %cx, %es
        movw %cx, %fs
        movw %cx, %gs
        movw %cx, %ds               # kernel data + stack
        movw %cx, %ss
        
        jmpl $gdtselector(KTEXT_DES), $multiboot_meeting_point
        multiboot_meeting_point:
        
        movl %eax, grub_eax         # save parameters from GRUB
        movl %ebx, grub_ebx
        
        xorl %eax, %eax
        cpuid
        cmp $0x0, %eax              # any function > 0?
        jbe pse_unsupported
        movl $0x1, %eax             # basic function code 1
        cpuid
        bt $3, %edx                 # test if PSE is supported
        jc pse_supported
        
        pse_unsupported:
                movl $pse_msg, %esi
                jmp error_halt
        
        pse_supported:

#include "vesa_prot.inc"

        # map kernel and turn paging on
        call map_kernel
        
        # call arch_pre_main(grub_eax, grub_ebx)
        pushl grub_ebx
        pushl grub_eax
        call arch_pre_main
        
        call main_bsp
        
        # not reached
        cli
        hlt0:
                hlt
                jmp hlt0

.global map_kernel
map_kernel:
        #
        # Here we setup mapping for both the unmapped and mapped sections of the kernel.
        # For simplicity, we map the entire 4G space.
        #
        movl %cr4, %ecx
        orl $(1 << 4), %ecx                 # turn PSE on
        andl $(~(1 << 5)), %ecx             # turn PAE off
        movl %ecx, %cr4
        
        movl $(page_directory + 0), %esi
        movl $(page_directory + 2048), %edi
        xorl %ecx, %ecx
        xorl %ebx, %ebx
        
        floop:
                movl $((1 << 7) | (1 << 1) | (1 << 0)), %eax
                orl %ebx, %eax
                movl %eax, (%esi, %ecx, 4)      # mapping 0x00000000 + %ecx * 4M => 0x00000000 + %ecx * 4M
                movl %eax, (%edi, %ecx, 4)      # mapping 0x80000000 + %ecx * 4M => 0x00000000 + %ecx * 4M
                addl $(4 * 1024 * 1024), %ebx
                
                incl %ecx
                cmpl $512, %ecx
                jl floop
        
        movl %esi, %cr3
        
        movl %cr0, %ebx
        orl $(1 << 31), %ebx                # turn paging on
        movl %ebx, %cr0
        ret

# Print string from %esi to EGA display (in red) and halt
error_halt:
        movl $0xb8000, %edi         # base of EGA text mode memory
        xorl %eax, %eax
        
        movw $0x3d4, %dx            # read bits 8 - 15 of the cursor address
        movb $0xe, %al
        outb %al, %dx
        
        movw $0x3d5, %dx
        inb %dx, %al
        shl $8, %ax
        
        movw $0x3d4, %dx            # read bits 0 - 7 of the cursor address
        movb $0xf, %al
        outb %al, %dx
        
        movw $0x3d5, %dx
        inb %dx, %al
        
        cmp $1920, %ax
        jbe cursor_ok
        
                movw $1920, %ax         # sanity check for the cursor on the last line
        
        cursor_ok:
        
        movw %ax, %bx
        shl $1, %eax
        addl %eax, %edi
        
        movw $0x0c00, %ax           # black background, light red foreground
        
        ploop:
                lodsb
                cmp $0, %al
                je ploop_end
                stosw
                inc %bx
                jmp ploop
        ploop_end:
        
        movw $0x3d4, %dx            # write bits 8 - 15 of the cursor address
        movb $0xe, %al
        outb %al, %dx
        
        movw $0x3d5, %dx
        movb %bh, %al
        outb %al, %dx
        
        movw $0x3d4, %dx            # write bits 0 - 7 of the cursor address
        movb $0xf, %al
        outb %al, %dx
        
        movw $0x3d5, %dx
        movb %bl, %al
        outb %al, %dx
        
        cli
        hlt1:
                hlt
                jmp hlt1

#include "vesa_real.inc"

.section K_DATA_START, "aw", @progbits

.align 4096
page_directory:
        .space 4096, 0

grub_eax:
        .long 0

grub_ebx:
        .long 0

pse_msg:
        .asciz "Page Size Extension not supported. System halted."